Maximal subthalamic beta hypersynchrony of the local field potential in Parkinson's disease is located in the central region of the nucleus

A pathological marker of Parkinson's disease is the existence of abnormal synchrony of neuronal activity within the beta frequency range (13-35 Hz) in the subthalamic nucleus (STN). Recent studies examining the topography of this rhythm have located beta hypersynchrony in the most dorsal part of the STN. In contrast, this study of the topography of the local field potential beta oscillations in 18 STNs with a 1 mm spatial resolution revealed that the point of maximal beta hypersynchrony was located at 53+/-24% of the trajectory span from the dorsal to the ventral borders of the STN (corresponding to a 3.0+/-1.6 mm depth for a 5.9+/-0.75 mm STN span). This suggests that maximal beta hypersynchrony is located in the central region of the nucleus and that further investigation should be done before using STN spectral profiles as an indicator for guiding placement of deep brain stimulation leads.